ICE: What is Immigration and Customs Enforcement, an agency now under fire

From nationwide protests against its policies to human blockades at the agency's office in Philadelphia, it may seem as though Immigration and Customs Enforcement is in the news nearly every day. So, what exactly is the agency whose name is filling your Twitter feed and adorning protest signs?

ICE is a relatively new agency. It started operations in 2003 and was created in part due to the Sept. 11 terrorist attacks. After the attacks, the Homeland Security Act consolidated existing independent agencies and created new ones to form what's now the Department of Homeland Security.

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According to the Senate Committee on Homeland Security and Governmental Affairs, ICE and other DHS agencies are supposed to work "to mitigate the threats presented by the potential for terrorists to enter our country, the effects of undocumented immigration and the potential for illicit substances to enter our nation at our borders and ports of entry." Other agencies within DHS include the Federal Emergency Management Agency and the Transportation Security Agency.

ICE works to fulfill three responsibilities.

The first and largest of these, according to the agency, is immigration enforcement, including tracking people in the country illegally. While ICE works with U.S. Customs and Border Protection, ICE says the majority of its work in immigration enforcement happens within the country's interior. ICE also monitors the workforce, enforcing immigration laws against employers who take advantage of immigrants' situation "to offer low pay and inadequate conditions."

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Although ICE is primarily known for work on immigration, it has other functions as well. The agency's second responsibility is investigating the illegal movement of people, goods, and money. It works to prevent human trafficking and the illegal trafficking of goods such as drugs, weapons and child pornography.

ICE's third major function is preventing terrorism. The agency works to prevent potential terrorists from entering the country and protect U.S. technology that, if in the wrong hands, could be used to attack the nation.

There are five major sectors within ICE.

Many immigration arrests happen under the jurisdiction of the agency's Enforcement Removal Operations division, which "enforces the nation's immigration laws in a fair and effective manner," according to its website.

Homeland Security Investigations is an "investigative arm" of ICE that looks into criminal activity happening within the United States and beyond its borders. HSI is largely responsible for investigating and preventing the illegal movement of goods, money, forged documents and people within the context of human trafficking.

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The third sector is the Office of the Principal Legal Adviser, which serves as ICE's representative in legal proceedings.

The final two sectors, Management and Administration and the Office of Professional Responsibility, play administrative roles. They oversee the other three sectors and work to maintain the organization's integrity.

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Since President Trump took office, the enforcement-removal arm has increasingly been deporting illegal immigrants with no criminal background. Under former President Barack Obama, the sector had primarily focused on those with serious convictions.

Under Trump, 64 percent of immigrants arrested by the Philadelphia ICE field office had no criminal convictions, an investigation by the Inquirer and ProPublica reported. Nationally, that number is 38 percent.

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In addition, the Inquirer and ProPublica investigation found that "collateral" arrests have been increasing under the Trump administration. In other words, the agency, while searching for criminals, has been arresting immigrants agents have come across by chance.

ICE has increasingly been the target of protests as debates about immigration practices have swirled under the Trump administration. Over the weekend, demonstrators in more than 600 cities, including Philadelphia, gathered to protest ICE and the Trump administration's immigration policies. Protesters have also set up camp outside ICE's Center City office several times in the past week.

Additionally, in a letter to Secretary of Homeland Security Kirstjen Nielsen, 19 senior ICE agents have called for the disbandment of the agency.

They said they believe the ERO and HSI branches of ICE should be split up into two separate agencies due to their different goals.

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"The two ICE sub-agencies have become so specialized and independent that ICE's mission can no longer be described as a singular synergistic mission; it can only be described as a combination of two distinct missions (i.e. 'Enforcement/Removal and 'Transnational Investigations')," the investigators wrote.

In separating the agency into two, the investigators said they believed that "transparency, efficiency and effectiveness" would be improved.